Aside from being a painful reminder that one’s beer is practically tasteless, squeezing lime juice into a bottle of brew can apparently have some nasty physical side effects. Dr. Scott Flugman, a medical practitioner from New York state, writes in October’s issue of Archives of Dermatology that the chemicals in lime juice, when combined with ultraviolet-A rays from the sun, can produce skin lesions he calls “Mexican beer dermatitis.”

The condition has earned that particular nickname because Flugman has seen it occur in patients who “were exposed to lime after drinking a popular Mexican beer.” Presumably, they missed the bottle, squirted lime juice onto their skin and then hung out in the sun. It’s layman’s lingo for phytophotodermatitis—a skin condition characterized by brown marks, redness or blisters. Those who come into contact with giant hogweed suffer something similar.

It’s true. I wasn’t drinking beer in Dominican Republic, but I was squeezing limes into a cup on my last day in DR to drink straight up. Thank goodness for the cloudy, rainy weather while we were there! I didn’t have to seek medical attention until I returned to sunny Canada. Luckily, I was already headed downtown for a Sarah McLachlan concert when the blisters and burning pain started. I just made a detour to the ER and then to the tropical diseases unit @ TGH.
Next time you look @ a bottle of sweet orange (or any other citrus) essential oil you’ll note the warning on the bottle regarding sun exposure.
Umbrellate (ex. carrots, parsnips, etc.) plant also often contain the same chemicals that will react to UVA.
The chemical is contained in the zest (skin) of the citrus, not the juice, but when squeezed, the chemicals from the zest mix with teh juice. Don’t put citrus juice on your hair to lighten it or you’ll be sorry you did!
Also causes hyperpigmentation in some cases.